(Not Applicable)
(Not Applicable)
1. Technical Field
The present invention relates generally to fire blocking. More particularly, the invention relates to the fire blocking of pallets.
2. Description of the Related Art
Several approaches have been used to develop pallets with enhanced physical properties. Many of these approaches incorporate the use of various mixtures of compositions to enhance the physical properties of pallets. Specifically, these compositions attempt to increase flame resistance, durability, and strength of pallets. One type of composition that has been utilized includes nanocomposite technology. Nanocomposites utilize many different materials that are intermingled on a nanometer scale. The use of nanocomposites to develop high temperature compositions with enhanced thermal stability and performance characteristics is disclosed in U.S. Pat. No. 6,057,035 to Singh. The invention in Singh provides high-use temperature, lightweight polymer/inorganic nanocomposite materials utilizing techniques that enhance the thermal stability of the nanocomposite systems from their current limits of 100-150xc2x0 C. to over 250xc2x0 C. Additionally, much research has been focused on the development of flame retardant materials in combination with fabrics to provide flame retardant qualities. Combining flame retardant materials with fabric is generally known. For instance, U.S. Pat. No. 4,950,533 to McCullough, Jr. discloses fabrics comprising a blend of substantially permanently or irreversibly heat set, non-flammable, carbonaceous fibers with polymeric fibers. Considerable time and effort has been expended in commercial industry to develop nonflammable and flame retardant fabrics. In the area of pallet technology, the efforts have focused on increasing a pallet""s ability to retard fire by the usage of methods involving the combinations of flame retardant materials in the composition of pallets, such as during the molding process. Additionally, the pallets in the prior art are monolithic in structure and incur difficulty when attempting to meet fire performance standards. Flame retardancy in the pallet industry is preferably measured according to the Underwriters"" Laboratory UL-2335 and/or FMRC fire performance protocol. Other organizations, such as the Grocery Manufacturing Association (GMA) and OSHA impose size and other restrictions on pallets depending on its particular purpose. These standards set minimum requirements that ensure fire safety and performance in the pallet industry.
Unfortunately, past efforts conducted to develop pallets exhibiting superior flame resistance have been problematic. Difficulty has been encountered in attempting to qualify pallets under standard safety guidelines, such as UL-2335. The problem to be solved is in developing a warehouse material handling pallet that meets the endurance, dimensional, load bearing, and weight parameters outlined by the Grocery Manufacturers Association (GMA) and OSHA ergonomic requirements while meeting the Factory Mutual Research Corporation and Underwriters Laboratories, Inc. Standard UL 2335 fire performance protocols. Consequently, there is a need for a pallet structure that meets the standards under these regulatory test concerning flame retardancy, while remaining cost efficient and effective for its particular purpose.
The present invention relates to an apparatus and method of fire blocking a pallet assembly that enhances the physical attributes of the pallet assembly while providing flame retardancy.
A pallet assembly according to the invention comprises at least one pallet member having external surfaces and a flame retardant material affixed to at least one pallet member so as to substantially cover all of the external surfaces of the pallet member. A pallet can include a container, tote bin, or any other suitable device used for the storage and transportation of items.
In accordance with the invention, a method of fire blocking a pallet assembly comprises the steps of providing a pallet assembly that can include at least one pallet member having external surfaces. The next step can include affixing a flame retardant material to at least one pallet member so as to substantially cover all of the external surfaces of the pallet member.
In this invention, a flame retardant material provides a covering to the pallet member and increases the fire performance of the pallet assembly. The flame retardant material utilized can increase the overall safety of the pallet assembly while providing enhanced physical durability. Flame retardant material suitable for use in this invention can include a flame retardant fabric. Affixing the flame retardant fabric to the pallet assembly provides resiliency to open flames. Open flames and other heat sources are common causes of pallet meltdown, thus creating dangerous fire hazards during storage and transportation. Affixing the flame retardant fabric to a pallet protects and prevents damage resulting from fire related occurrences and normal wear and tear. A blend of polymeric fibers can be included in the flame retardant fabric. The flame retardant fabric can be adapted to the dimensions of the pallet member. Adapting the flame retardant material to the dimensions of the particular pallet member can permit individual components of the pallet member to be fabricated. The flame retardant material also can include a flame retardant liquid. The flame retardant liquid can comprise an intumescent material. The intumescent material can be applied to a pallet member using a brush, roller or spray similar to application of ordinary paint. Required coating thickness depends on the substrate, severity of the heat exposure, and level of protection desired. The flame retardant material utilized also can include a flame retardant polymer such as polyetaraflouraethylene. Flame retardant synthetic fibers such as polyolefin fiber also can serve as the flame retardant material. Polyester and melamine fibers can also be utilized as the flame retardant material on the particular pallet member. Additionally, the application of flame retardant materials can provide aesthetic value to a pallet along with providing pallet assembly protection and flame retardancy.
In an embodiment of the present invention the flame retardant material can include a flame retardant metal. Stainless steel, copper, and aluminum are examples of metals that exhibit strong heat resistance while maintaining malleability which allow these metals to be integrated into a pallet assembly. The flame retardant material also can utilize nanocomposite technology in covering a pallet assembly. Nancomposites utilize many different materials intermingled on a nanometer scale. Nanocomposites can be made from a variety of starting materials including, but not limited to gases, minerals, and plastics. Nanocomposite technology provides the benefit of increased physical properties. Nanocomposites can provide higher heat distortion temperatures, less shrinkage, less warping, electrical conductivity and better fire performance. The nanocomposites utilized in the flame retardant material can include an organic-inorganic complex of material. The flame retardant material can be composed of a nanocomposite material comprising a polymer material integrated with a clay between 0.1% and 20% by weight of the nanocomposite. The weight of the clay used in the nanocomposite comprising the flame retardant material also can include clay between 0.1% and 10% and clay between 10% and 20% by weight of the nanocomposite. The clay utilized can include a silicate or silicate derivative such as montmorillonite (alumino-silicate). Nanocomposite technology has demonstrated a significant reduction in heat release rates on the order of 50 to 75% while increasing stiffness, heat distortion temperatures, cold temperature impact and other barrier properties. Nanocomposites also can be utilized in conjunction with flame retardant resins. Flame retardant resins further enhance the fire resistance of pallets. Examples of fire performance enhancing resin technologies used are zirconia, boron oxides, polybenzoxazine, polymers and carbonsilicone resin additives.
The flame retardant material can be adhered to the pallet member utilizing a variety of processes well known within the industry. For example, in-mold processing, extrusion, co-extrusion, lamination, and autoclaving are available techniques that are suitable for adhering a flame retardant material to a pallet member. Application of flame retardant material to a pallet member is an effective mechanism for increasing the fire resistance of the pallet assembly and reducing accompanying safety hazards associated with low fire resistance, while also exceeding fire performance standards for pallets under Underwriters Laboratory UL 2335 protocol for pallets.